Moistener for duplicating machines



Dec. 28, 1943. s. KOKAY MdISTENER lfOR DUPLICATING MACHINES Filed July 21, 1941 5 Sheets-Sheet 1 fiwenifir: Stephen )Yokay; By wawoniwfiaia'gg Dec. 28, 1943. KOKAY MOISTENER FOR DUPLICATING MACHINES Filed .July 21, 1941 5 Sheets-Sheet 2 Ira/197 126 Step/zen Kokqg- By,

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s. KOKAY MOISTENER FOR DUPLICATING MACHINES Dec. 28, 1943.

Filed July 21, 1941 5 Sheets-Sheet 4 Stephen Koka 91 z mwggg Dec. 28, 1 943. KQKAY 2,337,721

MOISTENER FOR DUPLICATING MACHINES Filed July 21, 1941 s Sheets-Sheet 5 Stephen Koka Patented Dec. 28, 1943 MOISTENER FOR DUPLICATING MACHINES Stephen Kokay, Chicago, Iii. assignor to Ditto, incorp rated. Chicago, lllL, a corporation of West Virginia Application July 21, 1941, Serial No. 403,355

16 Claims.

This invention relates to improvements in moisten ng means for duplicating machines and in particular to a sheet conditioning means for copy sheets which is provided with a moistening roller that contacts each copy sheet as it is fed into engagement with the drum and transfers a thin film of moisture to the surface of said copy sheet.

One of the principal objects of my invention is to provide an improved means for applying a thin film of moisture to the moistening roller. One of the means by which this has been done in the past is by the provision of a spreader member, usually a roller, in contact with the moistening roller, together with means for supplying solvent to the trough formed above the meeting line of the spreader member and the moistening roller.

Other and more particular objects are the provision of means to wash any accumulated lint from the surface of the moistening roller, or w other parts of the moistening mechanism, with an excess of solvent, together with means to remove such excess, to strain the lint therefrom, and to recirculate the same.

Further objects are to provide a moistener I which automatically controls the amount of solvent which is supplied to or allowed to accumulate in the trough between the spreader member and the moistening ro1ler thereby dispensing with the usual regulating means which must be manually adjusted by the operator to meet the operating conditions of each particular run. My improved moistener also cooperates with the driving mechanism of the duplicating machine in such a manner that when the machine is y;

stopped, the solvent is evacuated from said trough to such an extent that the solvent remaining therein will not cause overmoistening of the edge of the next copy sheet brought into contact with the moistening roller.

I have found that those features of my invention above outlined, together with other objects, features and advantages which will become apparent as this description proceeds, cooperate with each other to provide a moistener which is considerably more efficient and reliable than the prior known moisteners of this type.

In the drawings:

Fig. 1 is a sectional elevation of a preferred embodiment of my invention taken along line i-l of Fig. 2;

Fig. 2 is a sectional view taken along line 2-4! of Fig. 1;

Fig. 3 is a fragmentary sectional view taken along line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken along line 4-4 of Fig. 2;

Fig. 5 is a plan sectional view taken along line 5--5 of Fig. 3, the drum being left out;

Fig. 6 is a sectional view taken along line 6- 5 of Fig. 3;

Fig. 'I is a fragmentary plan sectional view taken along line 1-1 of Fig. 3;

Fig. 8 is a fragmentary sectional view taken along line 8-8 of Fig. 2;

Fig. 9 is a detailed sectional view taken along the line 9-9 of Fig. 6;

Fig. 10 is a fragmentary sectional view taken along line liilfl of Fig 5;

Fig. 11 is a fragmentary plan sectional view taken along line ll-ll of Fig. 3;

s Fig. 12 is a perspective view of the suction tube and spray tube assembly;

Fig. 13 is a sectional elevation taken on line l3l 3 of Fig. 2, showing the relation of the spray and suction tube assembly to the spreading and moistening rollers; and

Fig. 14 is a plan sectional view taken along line 14-44 of Fig. 3. I

Referring now to Fig. 1, reference numerals l8 and I9 designate the side frames of a duplicating machine, the side frames being associated with each other by means of a front frame member H1, which also serves as a base for certain parts of the machine, and by a rear frame member H8. A drum I! is suitably journalled in the side frame members. A motor III is mounted on the front frame member H1 and drives the drum through suitable driving means indicated generally at HZ. A pressure roller H6 is provided for the drum, this pressure ro1ler being suitably mounted by means which are not described in detail herein inasmuch as they form no part of my invention.

A feed tray H3 is disposed in front of the drum and is adapted to hold a stack of sheets thereon. A receiving tray H5 is provided at the rear end of the machine to receive the sheets as they are fed through the bight of the drum l1 and the pressure roller H6 to be duplicated upon.

A pair of feeding rollers 20 and 2d are disposed just in front of the bight of the drum and the pressure roller, the upper feeding roller 20, which also serves as a moistening ro1ler, being suitably journalled with respect to the side frames is and H! as shown in Fig. 2.

An interrupted gear 2! is associated with the drum and rotates therewith, and meshes with an idler gear 22. A gear 23 is associated with the upper moistening roller 29 so as to cause this roller to be intermittently driven by the rotation of the drum H. The lower moistening roller 24 is journalled in two pivoted arms 28, one adjacent each side frame, and is yieldingly pressed upwardly against the upper feeding roller 20 by suitable means indicated generally at 21. The upper feeding and moistening roller is preferably constructed of a somewhat yielding, substantially non-absorbent material such as rubber or neoprene having a Shore hardness of about 45 and is ground or turned to a true cylindrical shape. The lower feed roller is made of sponge rubber or neoprene and is considerably more resilient.

A thin film of solvent is applied to the surface of the upper feeding and moistening roller 20 by suitable means, which film is adapted to be transferred to the surface of a copy sheet which is being fed between the feeding rollers. For this purpose the moistening roller has associated with it a spreader roller 3! which is mounted alongside the moistening roller 20 and is yieldingly pressed against the same by mechanism which will be later described. The spreader roller preferably has fine indentations in its surface in the form of longitudinally running grooves 3la (see Fig. 13) of about .002 to .003 inch in depth, these grooves beingclosely spaced. The spreader roller 3! is substantially harder than the moistening roller. I have found it desirable to construct it of a suitablemetal such as brass, or of a resin composition such as that sold under the trade name Roulene. I have found that a hardness comparable to the hardness of brass works very well with a moistening roller having a Shore hardness of 45. v

Means are provided to seal the ends of the spreader and moistening rolls. This means is shown best in Figs. 2, 4, 5 and 8 and comprises spring pressed washers 32 and 33 placed on the ends of the moistening roller 20 and backed up by spring washers 3 and 35 which are held in place by collars 3B and 31 carried by the moistening roller shaft. The washers 32 and 33 are preferably constructed of a chromium plated metal so as to produce a smooth non-corrosive surface. The washers extend beyond the periphery of the roller 20 and overlap the ends of the roller 3| so as to form end barriers which cooperate with the rollers 20 and 3! to form a trough 38 above the meeting surfaces of the two rollers.

Means are provided to supply solvent to the trough 38 and also to remove the liquid therefrom so that there will be a continuous circulation of solvent in and out of the trough. By this means a measured amount of solvent is maintained in the trough during the operation of the machine, and the circulation thereof serves to wash the surfaces of the rollers free from lint or any other foreign matter which may adhere thereto.

A spray tube 39 is disposed above the trough, and consists of an inner delivery tube 40 and an outer distributing tube M, the distributing tube being provided with a number of openings 95 in the lower side thereof. These openings are more closely spaced to each other at the central portion of the tube than they are at the end portions thereof so that a greater amount of liquid will be supplied .to the central portion of the trough. A housing member 42 is disposed above the spray tube 39 across the machine so as to support the tube. This housing carries a vertically disposed wall 43 which is disposed substantially in alignment with the common tangent plane of the rollers 20 and 24.

At the lower edge of the wall 43 a suction tube 44 is mounted in such a manner that the lower surface thereof extends into the trough 38. This suction tube is provided with a plurality of openings 15 in its lower surface, these openings being more closely spaced from each other at the outer ends of the tube than they are at the central portion thereof.

The housing 12, together with the spray tube 39 and the suction tube 54 are mounted on a bar 46 which also serves as a mounting for the spreader roller 31 The bar it, as shown best in Fig. 6, comprises an intermediate rectangular portion 5i! having three spaced screw threaded apertures adapted to receive three screws 47, 48 and 49. The housing 32 is clamped in place by the head of the screw it and the heads of the screws d? and i9 act as guides so that the housing and the spray and suction mechanism carried thereby are rigidly connected to the bar 46. At the ends of the rectangular portion 50 the bar is circular in cross section and has two bearing sleeves 5i and 52 thereon, these bearing sleeves serving to support two depending arms 53 and 54 upon which the spreader roller 3| is mounted.

Referring now particularly to Figs. 2, 3 and 11, the spray tube 39 and suction tube 45 are shown as connected by suitable flexible tubes 55 and 56 to a liquid supply tank 51, The tank contains a pump cylinder 58 in which a pump plunger 59 operates, the pump plunger being pressed on its down stroke or spray stroke by a spring 60, and being retracted by a lever 6! that in turn is actuated by a cam 52 which is mounted on one end of the duplicating drum (see Fig. l). The lever 85 is pivoted on a cross bar 53 which extends from the side frame of the machine and it has a roller 54 which rides on the cam 52. A portion of the cam 62 indicated at 65 constitutes the portion which is engaged by the roller 54 on the spray stroke of the pump, that is, the down stroke. Upon the up stroke or suction stroke of the pump the portion 65 of the cam is engaged by the roller 64.

The outlet of the pump cylinder 58 is through a pipe 6'! that leads to a valve casing 68 in which a plurality of valves are mounted. The pipe 61 leads into the bottom of the casing 68 and opens into two channels (59 and 10 (see Fig. 3). The channel 19 leads to a spring closed valve H which is pressed into closed position by a spring 12. From this valve the pump outlet is continued to a passage 73 which is divided into two branches M and 15. Each of the branches 14 and T5 has a valve therein, as shown best in Fig. 7, the valve in the branch 14 being indicated at 16 and the valve in the branch 75 being indicated at 11. The branch 14 connects directly to the flexible spray tube 55. The branch 15 leads through a spring closed check valve 78 to a return pipe 13 which empties into the tank 51.

The valve block 68 has a suction inlet 80 which opens through a spring closed valve 8| to the passage 69 in the valve block 63. A spring 82 normally pushes the valve 8i upwardly into closed position but on the suction stroke, that is, the up stroke of the pump plunger 59, the suction in the pipe 61, and the channels 69 and 10 will cause the valve 8| to open and establish suction upon v the inlet 80. The inlet 80 and the flexible suction tube 56 are both connected to a sealed tank 83. The tube 56 is mounted on a pipe 84 that is sealed in the top of the tank 83. The inlet 80 has a pipe 85 extending through a side of the tank 83 and sealed to the wall thereof. The pipe 85 has an upturned end .88 that extends up to a point spaced a short distance below the top of the tank 83.. At the top of the tank 83 there is a fiange 81 on which the upper end of a screen receptacle 88 is mounted. This top portion is clamped in place by a cover 89 for the tank 83. It will be understood that suitable Packing is used, although not indicated, so that the cover 89 effectively seals the tank 83 to make it airtight. The screen receptacle 88 is constructed of very fine Wire mesh of a wire that will not corrode under the effect of the solvent liquid used in duplicating machines. This receptacle is fiattened at one side where it is covered by a solid plate 88a and is held away from the top portion 88 of the pipe 85 by a cross bar 90 in the tank 88. The pipe 85 also has an overflow branch 9! that extends down into the tank 51 and is open at the bottom as indicated at 92, this opening being near the bottom of the tank 51.

In operation the moistening fluid supply and return mechanism just described works as follows: on its down stroke, the pump plunger 59, after the plunger passes the inlet openings 88 to its cylinder 58, will force liquid out through the pipe 81 and the valve casing 68 and up through the tube 55 to the spray tube 3.9. This stroke is of a predetermined length and by properly positioning the valves I8 and H the fixed quantity of liquid pumped can be proportioned so as to supply the desired amount to the rollers 29 and iii The liquid is discharged into the trough between the rollers and the delay between the time the pump is actuated on its spray stroke and the beginning of the return stroke of the pump (when the roller 64 starts to climb the cam portion 68) is sufficient to permit this discharge. On the return stroke of the pump the plunger 58 is raised, thus creating a suction or vacuum in the valve casing 68. The valve II closes as soon as the spray stroke is finished and on the suction stroke of the pump the valve 8| opens and the suction is applied to the top of the tank 83 through the pipe 85. The suction applied is sufficient to empty the air out of the suction chamber or tube 44 and the pipe 58 and to start the flow of liquid from the pool in the trough between the rollers down through the pipe 56 and the pipe 84 into the tank 83. Of course, as soon as the plunger 59 moves up past the openings through its cylinder at the bottom of the tank 51 it no longer acts to create a vacuum in the pipe e1 or the valve casing 88, and the valve BI closes. However, once the flow is started through the suction tubes 44 and 56 it continues until air begins to be drawn in at the trough between the rollers, this result being attained because the tubes act as a siphon. The level of liquid in the tank 83 is thus being continually built up by the liquid returned from the trough between the rollers except as such liquid drains on through the pipe 86 and the overflow pipe 8! into the tank It has been found advantageous to keep the screen receptacle 88 spaced from the top of the pipe 88 for preventing any tendency for the liquid to climb the screen so as to cause undesired flow through the pipe 85 and thus unduly lower the level of the solvent in the tank.

The particular advantage of this moistening construction lies in the fact that it is possible to deliver a measured amount of liquid to the trough between the rolls and then withdraw the excess liquid so as to prevent an overflow of the trough while maintaining an adequate supply of liquid iii for moistening purposes. It is necessary of course to avoid too great a pump stroke that would cause the trough to be filled above the end seals and the tops of the rollers, but the suction device will take care of emptying the trough down to the safe level regardless of the amount of liquid delivered to the trough. This is because the suction device is really independent of the pump stroke once it is started and acts as a siphon to remove all the liquid necessary to bring the liquid level down to the inlets to the suction pipe.

The suction tube is so constructed as to fit down closely in the trough between the rollers 20 and 3|. Th clearance may be as low as .040 inch between the tube and each roller. This enables the tube to clear the liquid from the trough 38 to a point where any liquid left is of such small amount as to cause no damage. The end seals 32, 33 are sufiiciently large to prevent overflow at the trough ends. They travel with the moistening roller 28 and Wipe the ends of the spreader roller 3! so as to efiectively prevent end leakage. To avoid the possibility that liquid might run back over the spreader roller 3| from the spray tube 39 I provide a baffle plate 96. This plate is mounted on the bar 48 and extends downwardly and toward the trough 38 beyond the top of the roller 3 I The means by which the roller 3| is pressed against the roller 28 comprises (Figs. 5, 6, 8 and 10) two brackets 98 and 99 mounted on the side frames l8 and i9, lever arms I and I8: pivoted thereon and having lugs I82 and I83 engaging corresponding lugs I84 and on the arms 54 and 53, respectively, between which the roller 3! is rotatably mounted, threaded rods I86 and I ill! pivoted on the brackets 98 and 89 and passing through the lugs I92 and H33, respectively. adjusting nuts I08 threaded on the rods Hi6 and IUTI, and. springs I89 onthe rods and between the nuts 18 and the lugs I82 and I83. The pressure of the roller 3I against the roller 28 is adjusted by turning the nuts I08.

The lugs I04 and [c5 also serve to mount a strip H8 which supports a copy sheet guide 91 that overlies the end of the feed tray I I3.

The manner in which the liquid solvent is supplied to the trough 38 and removed therefrom effects a washing of the surfaces of rollers 28 and 3|. The spray tube 39 discharges more liquid near the center of the rollers than at the ends, and the suction tube has more openings at the ends of the tube so as to draw off the liquid faster at the ends of the rollers. The solvent pump in the tank 51 is preferably arranged for delivering a substantial excess of solvent to the trough 38 so that there is a substantial fiow of solvent along the rollers 28 and al toward their ends so as to remove any foreign matter, such as lint, that is washed from the surfaces of the rollers. By arranging for the removal of almost all excess solvent from the trough 38 on each revolution of the drum I! so as to leave the trough practically empty at each interval when the intermittently driven rollers 28 and 8% are stationary, I provide that the tendency for the sol-- vent to work its way downwardly between the rollers and between the washers and the ends of the rollers is effectively combatted, with the result that the control of the solvent is substantially improved.

While I have described the preferred form of .my invention it is obvious that it is capable of modification. Changes therefore may be made in the various features without departing from the scope of the invention as defined in the following claims, wherein it is my intention to claim all noveltyinherent in th 'device in view of the prior art. l

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a moistening device for a wet process duplicating machine of the type wherein the solvent is circulated from a supply tank tothe moistening roller and back, the combination including a suction conduit for the return of solvent together with a strainer associated therewith to remove lint from the solvent, said strainer comprising a receptacle, a removable cover therefor, and a removable screen disposed within said receptacle and adapted to be held in position by the coaction of said cover with said receptacle, a portion of said conduit communicating with the interior of said screen, and another portion of said conduit communicating with the interior of said receptacle outside of said screen, the end of said last named portion being positioned close to the top of said receptacle, and spaced from said screen.

2. In a moistening device for a duplicating machine of the type wherein solvent is refluxed between a container and the trough between a moistening roller and a spreader member, means to supply a measured amount of solvent to the trough, said means including a pump disposed within said container, means to operate said pump, a supply conduit leading from said pump to the trough, a by-pass conduit extending from said supply conduit to said container, and adjustable valves associated with said supply conduit and with said by-pass conduit whereby the quantity of solvent passing through said supply conduit may be proportioned.

3. In a wet process duplicating machine, a moistening roller, a spreader member disposed adjacent thereto, means to urge said spreader member into contact with said moistening roller to form a trough between the two, means for sealing the ends of said trough, means to supply solvent to said trough, and a suction tube disposed within said trough, the surface of said tube being spaced from the surface of said roller by a distance sufliciently small so that the surface attraction of the tube for the solvent will cause the solvent to be disposed all along the length thereof.

4. In a moistening device for a duplicating machine, a moistening roller, a spreader member cooperating therewith to form a trough at the side of said roller, a supply tube disposed above the trough, said supply tube being provided with downwardly facing perforations, the spacing between said perforations at the end portions of said tube being greater than the spacing at the central portion of said tube, and a suction tube disposed Within said trough and provided with o a ions in its underside, said perforations being spaced more closely together at the outer ends of said suction tube than at the central portion thereof whereby an excess oflsolvent will be applied to the central portion of said trough and will flow along the roller toward its ends and be removed by said suction device so as to provide a washing action, and means at the ends of the roller to prevent the solvent from running over the end surfaces of said roller.

5. In a moistening device fora duplicating machine for applying solvent to the faces of a series of copy sheets in succession, the combination of ing the moistening roller, means to supply solvent to the trough formed between said spreader roller and moistening roller, said means comprising a pump to supply a measured amount of solvent to said trough at regular intervals, cam means on the drum to actuate said pump, and means associated with said pump and extending into said trough to remove the solvent from said trough upon the reverse stroke of said pump, said cam means being so arranged with respect to the normal stopping pos tion of said drum as to permit of a reverse stroke of said pump before the drum comes to rest whereby only a small amount of fluid will remain in said trough when said duplicating machine is not in use.

'7. A duplicating machine comprising a drum, a pressure roller for cooperation therewith, a pair of feeding rollers cooperating with said drum and pressure roller, and means for applying a thin film of liquid to one of said feeding rollers,

said means comprising a spreader roller mounte for contact with said last named feeding roller, means for resiliently urging said spreader roller against said feeding roller to form a trough for the reception of a small body of liquid, flanges associated with said feeding roller at each end thereof, and overlapping the ends of said spreader roller, means for resiliently urging said flanges against the end surfaces of said feeding and spreader rollers to seal the ends of said trough, a supply tube disposed above said trough, a suction tube extending into said trough, a supply tank incommunication with said supply and suction tube, a strainer between said suction tube and said tank, and means for causing solvent to circulate from said tank through said supply tube to said trough, and back through said suction tube and strainer to said tank.

8. In a moistening device for a duplicating chine having a moistening roller and a spreader roller mounted adjacent thereto to form a trough, means to circulate solvent through said trough comprising a tank containing a supply of solvent and mounted so that the free surf-ace of the sol-- vent therein is lower than said trough, a pump disposed within said tank and having an inlet and an outlet valve a supply conduit extending from said outlet valve to said trough, a suction conduit extending from said trough to said inlet valve, means to actuate said pump whereby solvent will be supplied to said trough through said outlet valve, and will be removed from said trough by suction applied through said inlet valve from the pump, auxiliary inlet means for said pump including a port communicating with the solvent in said tank, a strainer disposed in said suction conduit, and communicating means extending between said suction conduit and said tank from a point between said strainer and said inlet valve on the former to a point belowthe free surface of the latter, the lift between said first point and said free surface being greater than the lift between the inlet of said suction conduit and the highest point thereof whereby the suction of the pump at said inlet valve will be effective to start a siphoning action through said suction conduit and communicating means which may continue independently of the pump.

9. In a moistening device for a duplicating machine for applying solvent to the faces of a series of copy sheets in succession, the combination of a moistening member having a downwardly movable face portion, a member in pressure relationship with said downwardly movable face portion and forming therewith a trough adapted when the parts are stationary to hold a supply of liquid in position and adapted when said face portion is moved downwardly to permit a film of the liquid to escape thereon, means for feeding liquid to said trough so as to form a substantial pool therein, means for pressing a copy sheet against the moistening member for movement therewith and for the application of liquid from the moistening member to the sheet, means for driving said moistening member, and means made effective at about the end of each sheet moistening operation to withdraw from the trough any liquid therein in excess of a predetermined minimum amount substantially less than the maximum amount in the pool.

10. In a moistening device for a duplicating machine for applying solvent to the faces of a series of copy sheets in succession, the combination of a moistening member having a downwardly movable face portion, a member in pressure relationship with said downwardly movable face portion and forming therewith a trough adapted when the parts are stationary to hold a supply of liquid in position and adapted when said face portion is moved downwardly to permit a film of the liquid to escape thereon, means for feeding liquid to said trough so as to form a substantial pool therein, means for pressing a copy sheet against the moistening member for movement therewith and for the application of liquid from the moistening member to the sheet, means for driving said moistening member, means comprising a siphon for withdrawing from the trough any liquid therein above a predetermined low level, and means comprising a pump effective on each sheet moistening operation to fill said siphon for giving it a liquid withdrawing operation.

ll. In a moistening device for a duplicating machine for applying solvent to the faces of a series of copy sheets in succession, the combination of a moistening member having a downwardly movable face portion, a member in pressure relationship with said downwardly movable face portion and forming therewith a trough adapted when the parts are stationary to hold a supply of liquid in position and adapted when said face portion is moved downwardly to permit a film of the liquid to escape thereon, means for feeding liquid to said trough so as to form a substantial pool therein, means for pressing a copy sheet against the moistening member for movement therewith and for the application of liquid from the moistening member to the sheet, means for driving said moistening member, a suction tube extending along said trough with openings near the bottom of the trough, means adapted to cooperate with said suction tube for withdrawing liquid from the trough by a siphoning effect so as to lower the liquid in the trough to a predetermined level, and means adapted on each sheet moistening operation to fill said siphoning means for making it effective for withdrawing from the trough any liquid therein in excess of a predetermined minimum amount.

12. In a moistening device for a duplicatin machine for applying solvent to the faces of a series of copy sheets in succession, the combination of a moistening roller, plates concentric with the roller at opposite ends thereof and of a size to extend outwardly beyond the cylindrical surface of the roller and held normally from movement away from the roller so as to turn therewith, a spreader member having a close working fit between. said plates and in pressure relationship with the downwardly moving side face of said roller so as to form with the roller and the plates a trough adapted to hold a supply of solvent effectively when the roller is stationary and to permit a film of the solvent to pass downwardly out of the trough when the roller is rotated, and means for rotating said roller.

13. In a moistening device for a duplicating machine for applying solvent to the faces of a series of copy sheets in succession, the combination of a moistening roller, plates in the form of disks mounted loosely in concentric position with the roller at opposite ends thereof and of a size to extend outwardly beyond the cylindrical surface of the roller, yielding means normally pressing said plates firmly against the ends of the roller, a spreader member having a close working fit between said plates and in pressure relation ship with the downwardly moving side face of said roller so as to form with the roller and the plates a trough adapted to hold a supply of solvent effectively when the roller is stationary and to permit a film of the solvent to pass downwardly out of the trough when the roller is rotated, and means for rotating said roller.

14. In a moistening device for a duplicating machine for applying solvent to the faces of a series of copy sheets in succession, the combination of a moistening roller, a spreader roller in pressure relationship with the downwardly moving side face of said moistening roller, plates in the form of disks rotatably mounted on the end portions of one of said rollers and of a size to extend beyond said roller into engagement with the ends of the other roller so as to serve with said rollers to form a trough adapted to hold a supply of solvent effectively when the rollers are stationary and to permit a film of the solvent to pass downwardly between the rollers when they are rotated, means for pressing said plates forcibly against the ends of the rollers, and means for driving one of said rollers.

15. In a mechanism for moistening copy sheets in a liquid process duplicating machine, the combination of a member having a downwardly movable face portion and a member cooperating therewith to form a trough between them adapted to hold a supply of liquid and adapted upon downward movement of said face portion to pass a thin even film of liquid on said face portion below the trough, means cooperating with said movable member for carrying a copy sheet forwardly in engagement therewith for taking moisture therefrom, a pump, means for actuating said pump in timed relation to the movement of copy sheets past said moistening means, liquid delivering means for feeding liquid into said trough, connections between said liquid delivering means and said pump adapted on a pressure stroke of said pump to apply the full pressure of the pump on said liquid delivering means for feeding liquid to said trough, and other means connected with said pump adapted on a suction stroke of the pump to take the major portion of the liquid from said trough at about the end of the duplicating operation on each copy sheet in turn.

16. In a moistening device for duplicating machines, the combination of a moistening roller, a spreader member in engagement with the downwardly moving side of said roller to form therewith a trough for a supply of liquid solvent, a tank for solvent, means for feeding solvent from said tank and discharging it into said trough, the roller and spreader member cooperating to feed a portion of the supplied solvent from the bottom of the trough on the moistening roller as the roller turns, means cooperating with said moistening roller for carrying a sheet forwardly in engagement with the moistened surface of said roller to take the solvent therefrom, a suction device having its inlet portion in said trough and opening toward the bottom of said trough to draw off the solvent and solid matter washed from the surface of said roller by the solvent, said suction device returning the drawn off solvent to said tank, and means to remove solid matter from the drawn ofi solvent.

STEPHEN KOKAY. 

